Accidentally added synthetic. Now what?

I've read through some of the raging debates regarding oil. I'm new to all of this car stuff and did my first oil change last night. (I've always gone to a minute lube type place in the past). I sent my wife to pick up some oil while I was at work and I added it without really reading the container (other than to make sure it was 10W30).

When I saw the receipt later, I fell out of my chair as the oil was $6 a quart. Now, I see that it was synthetic oil and wonder what I should do. I haven't actually driven the Jeep since I added the oil but did run it for a minute or two after the change to check the level. Should I remove it and put in the old fashioned oil in order to prevent the leaks that I read will surely come?

This is a 1990 with 205,000 miles and I don't know the history. I was told that the engine was rebuilt about 50,000 miles ago but who really knows.

Synthetic oil does not cause leaks, it removes deposits that may be clogging up leaks that already exist

I switched mine to synth at 180k and love it, havn't had anything but more horsepower since

I've been running synthetic for years. Change every 6 mos. Good filter.
No leaks that didn't already need fixing. Go with it. If you want to drain & refill you can do that too. 220K miles & still strong!!

I prefer the synthetic.

Everyone's got an opinion.

I don't see anything wrong with synthetic. Since you're saying you were rebuilt about 50K ago, you're at about the right point to switch anyhow.

You can get away with the extended change intervals - if you're not regularly operating in dusty environments, or you're not doing all "short-trip" driving (and don't get the oil heated up enough to get all the condensed water out.)

I'd normally suggest putting 30-50kmiles on a new or overhauled engine, but you sound like that's already done for you (the extra lubricity of synthetic oil can interfere with engine "break-in.")

I'd want to make sure that it wasn't an "energy saving" oil - I think both synthetic oils and dead dinosaurs are subject to the drastic lowering of organometallic additives as antiscuff additives - which has been responsible for flat tappet cam failure. If the oil is not "Energy Saving" (I don't recall the API spec - SM?) or it does have a Diesel rating, you should be fine. If it fails either one of those checked - change it before it causes you some expensive problems...

Just drive it, at around 3,000mi drop the filter and put a new one on, add 1 quart of Mobil-1 'High Mileage' oil and continue on. Check your dipstick regularly, if the oil gets to dark to read thru at say 1000mi drop the filter and add a quart, thats the synthetic penetrating all the sludge and letting it flow again. If the price of the oil really bothers you use a 50/50 mix of say mobil 10W30 normal oil and Mobil-1, gives you the added lube of synthetic w/o the shock of 6 quarts
Just use a good filter, Mobil-1, K&N, Purolator pure one and stay away from Fram, stp, the cheapies.

I would change it if you alreadyu had regular oil in there. If not stay with the syn. I use it and it seems to work great. Now that I have been using it my oil doesn't seem as broken down as it used to when I go to change it. COuld just be in my head though lol

5-90 said it best.

You can go back and forth. If you ran this oil 5K ,then added the dino it was usually getting every 3K, It would'nt be a problem.

This turned out to be a serendipitous event. After reading the posts on this thread and the excellent article I found at http://www.mr2.com/TEXT/synth_oil.txt, I think I'll keep using the synthetic and fix any leaks as they arise.

I didn't realize you could change the oil less frequently so the price isn't really an issue. It seems that synthetic is far superior for many reasons according to what I've read.

Just make sure you change the filter and add the required oil.

Will do. Thanks. Which filter do you use?

I flip between Mobil-1, K&N and Mopar, pretty much now just Mobil-1 filters since they became about $3 cheaper than K&N at the local parts store. I have been hunting a source where I could buy a case or two of them at once. There used to be a place on Long Island that sold them for $4 but they vanished back in 03 right after I bought 3 cases.

furrymcmonst said:

This turned out to be a serendipitous event. After reading the posts on this thread and the excellent article I found at http://www.mr2.com/TEXT/synth_oil.txt, I think I'll keep using the synthetic and fix any leaks as they arise.

I didn't realize you could change the oil less frequently so the price isn't really an issue. It seems that synthetic is far superior for many reasons according to what I've read.

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My other advice does stand - get the API rating on the oil they used! If it's "Sx/Cy," you're good. If it doesn't have a "C" rating, get an oil that does. If they say it's "Energy Saving," change it straight away. The new "Energy Saving" oils, as I mentioned earlier, lack a necessary additive in useful amounts that we need (with 'flat tappet' cams. Another reason that some of us are working on ideas for "roller tappet" cam profiles...)

I wonder why you say if it doesn't have a C rating, don't get it.....

Because the New Mobil-1 EP is API SM/CF ILSAC GF-4.


If you find some stock pile of Mobil-1 API SL Gasoline oil, jump on it!!!!! Or any old HD's Cl-4, !!!!

Energy conserving does not necessarily mean its got drastically low Phosphorus amounts... IIRC It is a indendent org. that does the testing to determine the mpg gains or drops using said oil.

I had a Fresh bottle of Royal Purple that was API SL, and Energy Conserving in the bottom of the 'donut' 1000ppm zinc and phos.

I think what your trying to say if it has a C rating as in CJ-4 (current Diesal rating) (Delo, Rotella, Delvac...) It's ok to use. All three of those are showing up Moly and Boron now as the new anti-scuff's replacing the once 1500ppm zddp in HD oils down to about 1000.

5-90, I checked the oil that I used and it has the following ratings.

Valvoline SYNpower
API Services SM/SL, CF, ILSAC GF-4, ACEA A1/A5 PROTECTION

Thanks for the reminder.

Sounds good.

The reason I say to check for a Diesel rating is simple - Diesel engines still use flat-tappet camshafts, and the catalytic converter has only recently (I think) caught on with the Diesels anyhow. So, they can still use organometallic anti-scuff additives without all the complications that the EPA is trying to sell us on with gasoline engines (primarily degraded catalyst efficiency. Since there are many of us out here still using flat tappet cams, and many enthusiasts of older vehicles, I find their policy a bit short-sighted - along with just about every other segment of the market. I don't even like new cars...)

API ratings being what they are, if you don't have the "Energy Saving" logo on front, you probably have the C rating on the back - but it's quick to check. But, until they get around to using an anti-scuff additive that can work as well as ZDDP - either in lower concentrations, or without catalyst side-effects, we're going to have to pay attention to our oil - or pony up for additives like GM's EOS (which can get spendy fast...)

(It's not phosphorous content that causes the issue - it's the reduction in zinc compounds. I don't recall what "ZDDP" stands for without looking it up, but it's an organometallic salt of zinc. That happens to contain phosphorous. However, it's the zinc that is the primary component, from what I've been able to find out so far using my Google-Fu.)

RichP said:

I flip between Mobil-1, K&N and Mopar, pretty much now just Mobil-1 filters since they became about $3 cheaper than K&N at the local parts store. I have been hunting a source where I could buy a case or two of them at once. There used to be a place on Long Island that sold them for $4 but they vanished back in 03 right after I bought 3 cases.

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I've been running bosch filters, same OEM as K&N (champion IIRC) and only ~$5 at AZ, been happy with em so far

I'll usually use Wix (easier to find) or Baldwin (good luck!) Fram can't catch a cold - much less oil contaminants... I'd rather use a "cartridge" style case and a bog roll with the core pulled out than Fram...

FoMoCo said:

I've been running bosch filters, same OEM as K&N (champion IIRC) and only ~$5 at AZ, been happy with em so far

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I have never seen bosch filters in any stores around here, actually I have never seen a bosch filter period. I have noticed that there are only a few of the parts stores that even carry fram. It's all Purolator, Mobil-1, K&N and AC/Delco. Only the big box mart stores carry Fram anymore.

Zinc DialkylDithioPhosphate. It is a zinc compound but the EPA is more concerned with the Phosphorus.

ExxonMobil has a nice Q and A somewhere, hitting on the points of zddp and PAO. True or not, who knows. is 800ppm zddp enough for a flat tappet? maybe, but why do they keep cutting and cutting it! Saw a virgin sample of penzzoil that had 300ppm each!!!

RyanM said:

Zinc DialkylDithioPhosphate. It is a zinc compound but the EPA is more concerned with the Phosphorus.

ExxonMobil has a nice Q and A somewhere, hitting on the points of zddp and PAO. True or not, who knows. is 800ppm zddp enough for a flat tappet? maybe, but why do they keep cutting and cutting it! Saw a virgin sample of penzzoil that had 300ppm each!!!

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Thank you. My last O-chem course was ca. 1987, so it's been a couple of whiles...

Yeah - the problem was that the phosphorous was clogging up the cat matrices, but it's the zinc that acts as the anti-scuff. However, to reduce the phosphorous content, they've been reducing zinc in tandem (haven't come up with a way to replace the zinc in the oil.)

But, they keep cutting it because the EPA is crawling up their collective arse over catalyst failure...